The present invention relates to an impact tool, blade and cutting method used by telecommunications personnel for insertion and removal of conductor wire in connector blocks and the like. More particularly, the present invention relates to a wire insertion, hand-operated impact tool blade and method which provide in a simple and reliable manner a selectively actuatable cutting function and from one location, two impact setting positions, a setting for no impact where only cutting is desired and blade release from a pouch.
Impact tools for effecting an electrical connection have long been known as shown in U.S. Pat. No. 2,774,133. Such tools basically utilize the operating mechanism of a self-triggering nail set or center punch but with a specially designed operating plunger. A similar form of insertion tool is shown in U.S. Pat. No. 2,960,864 in which a plunger is compacted by a hammer which, in the rest position, is biased by a compression coil spring such that the hammer is canted or tilted relative to the longitudinal axis of the tool.
Another form or insertion hand tool is disclosed in U.S. Pat. No. 3,074,155. A cylindrical detent in a hammer is biased outwardly by a spring and extends partially through a circular opening in a barrel. Upon application of inserting force by an operator who grasps the tool by the handle and pushes a pin into a receptacle, the outer handle is moved relative to the barrel and progressively cams the detent inwardly against the spring bias. When the detent has been cammed inwardly to a sufficient extent, the hammer is triggered, and the kinetic energy of the hammer is transmitted to a rod and thence to the connector.
Similar types of impact tools are shown in U.S. Pat. Nos. 3,177,952 and 3,279,044.
Another type of impact tool is known as a termination tool for use in the communications industry which inserts an insulated wire into the fork of a bifurcated termination clip and cuts the wire beyond the termination. Typically, as shown in U.S. Pat. No. 3,708,852, the tool has a manually operable handle and a terminal blade movably mounted with respect to the handle. A spring is provided between the blade and handle so that, upon increased pushing of the handle by an operator, a hammer stroke from the handle onto the blade is produced to finalize and cut off the termination with a minimum amount of physical effort. To this end, a hammer is slidably movable in guide surfaces in an upper part of the handle. A spring engages against the hammer which normally rests against a stop surface in the handle. An adjusting screw is also provided in the handle to increase the force by which the at-rest hammer is urged against the stop surface. The hammer has a bore which receives a pin and a cross-bore which receives a sear having a release hole urged outwardly of the cross bore by an elastomeric pad or the like. A cam surface is formed on the side of a guide surface in the handle adjacent the hammer and is positioned so that when the hammer is in its rest position, the sear is permitted to move to the right with its release hole out of alignment with the bore in the hammer and with a pin of an anvil. As manual force is applied to the top of the handle in a direction to cause a wire to be seated in a clip of a telephone connection block, the hammer spring and a return spring are compressed. The hammer is moved upwardly, and the sear is moved inwardly by the cam surface until the release hole aligns with the bore in the hammer at which point a slide shoulder on the anvil is above the stop surface against which the hammer normally rests. Upon release, the hammer is driven downwardly by the compressed power spring so that the lower surface of the hammer strikes the slide shoulder. The hammer blow causes the blade to seat and cut off the wire.
Similar types of termination tool blades are shown in U.S. Pat. Nos. 3,883,316; 4,161,061; 4,241,496; and 4,696,090. In the first-mentioned patent, the terminal tool uses a reversible blade. In the second-mentioned patent, the reversible blade uses an L-shaped bayonet slot and a cam follower spring in a groove on the tool slide to interlock the blade and yet allow it to be quickly removed. The third-mentioned patent provides a blade storage pouch in the tool handle which releasably retains with one rotatable knob a termination blade. In addition, a second rotatable knurled knob is provided to shorten and lengthen a power spring between two positions for setting the impact at either a high level or a low level for delivery to the slide. In order to obtain a seating function without a cutting function the blade, such as the "66" blade (a cutting edge at only one of the ends) available on the market, must be removed from the tool and reversed to present the seating edge which does not also have the knife edge as is present on the other end of the blade. The fourth-mentioned patent discloses a scissor-like removeable blade assembly on which the cutter member is always in the actuator position and is used on the tool described in the third-mentioned patent.
More recently, other types of insertion tools and electrical connector methods have been developed as shown for example, in U.S. Pat. Nos. 4,567,639; 4,624,521; 4,663,838; and 4,682,412. One such connecting tool is the "BIX"-blade marketed by Cook Electric and designed to seat 22-26 gauge wire in miniature quick-clips. As the tool is withdrawn, a spring loaded shear cuts off the free end of the wire. The tool can also be adjusted to seat the wire without cutting if looping is desired.
Heretofore, however, it has not been known how to provide a simply constructed and highly reliable impact tool having the ability to adjust the impact force, store the blade in a pouch using the friction of a coil spring tightening around the center section of the tool and the versatility selectively to cut wire without impact, impact without cutting or both cut and impact. For instance, although a seating through impact without cutting was possible, as in the above-mentioned "66" blade system, the converse was not true. Moreover, it was necessary to utilize multiple knobs to effect blade release and changes in impact setting as shown in U.S. Pat. No. 4,241,496.
An object of the present invention is, therefore, to provide a simply constructed and highly reliable tool having compact force, blade storage capability and a mechanism which switches between cutting and non cutting positions of the blade in a particularly advantageous manner, and a cutting method which provides reliable cutting of wires.
A further object of the invention is to provide a modified blade design with a possible scissor-like cutter which allows engagement and disengagement of the blade in a simple and efficient manner.
It is another object of the present invention to construct an impact tool with a minimum number of components while providing maximum versatility.
It is still a further object of the present invention to configure an impact tool in as compact and streamlined a manner as possible so as to be easily adjustable and comfortable in the hands of most telecommunications equipment personnel.
Yet another object of the present invention is to provide a switch for the cutting function which is easily accessible and operable by the thumb of the operator's hand merely by sliding a switch between two positions, namely the cut and the no-cut positions.
These objects have been achieved in accordance with the present invention by constructing the tool and blade such that a slidable switch on the tool handle moves a cutter actuator axially inside the tool handle to and from the end of a pivotable scissor blade.
Another feature of the present invention which accomplishes the foregoing objectives is a cam located in the rearward portion of the handle to cooperate with a cam surface on the inner wall of the handle to move from a "NO" impact setting to a "LO" impact setting, then to a "HIGH" impact setting and back to the "NO" impact setting.
Yet another feature of the present invention is the utilization of a deactivator member provided within the handle so as to allow the tool to be put into the cutting position without an impact function.
A pouch at the end of the handle sets the two impact settings and the no-impact setting by turning the cam on the handle in one direction. The pouch has an axial opening in the rear end for holding a termination blade or the like and for releasing the same by rotation of the pouch in the opposite direction.
A cantered or tiltable hammer is arranged in the handle and is urged toward a rest position by a relatively stiff coil spring which acts as the power spring for causing the impact blow against a slide when the hammer becomes longitudinally aligned with the axis of the slide.
In the event a cutting function is desired along with the impact seating function, the switch on the handle is thumb actuated toward the forward end (the blade end) of the tool. An actuator connected with the switch is pushed toward the forward end so that its U-shaped legs surround the rear end of a pivotable cutter for a scissor type blade. A trigger cam engages in a slot in the actuator. The slot is sized and configured such that, when the switch is at the "CUT" position, the trigger cam will move to the opposite end of the slot as the handle is moved relative to the slide. The basic movement of the tool by pushing the handle to effect impact is generally otherwise known.